The invention relates a flow heater for water in a machine for producing hot water, and in particular for a machine for the preparation of brewed beverages. Such a machine includes a water tube and a heating tube connected to the water tube in a heat conductive manner.
Prior art flow heaters of this type have until now been designed so that the heating tube over its entire length along the water tube has a uniform heating output. This is counterproductive toward an optimal degree of effectiveness, and it results in a high exposure to heat of the housing elements usually found in the vicinity of the heating and water tubes. The geometric shape of the water tube and, therefore, of the heating tube as well as the conrresponding spatial arrangement within the housing have, until now, been designed according to the geometric conditions of the respective housings rather than the optimalization of the operational process and heating efficiency.